Protected Lobby - Travel Distance in Flats

[nemodadog]

Hi,
In the protected lobby within flats, the maximum travel distance is noted as being either 4.5M or 7.5 metres depending on whether ventilation is provided. These figures are stated in ADB...does anyone know where the figures came from and teh basis behind them..ie why not 5.5M or 10metres etc??

Thanks

[wee brian]

Committee wisdom - the original theory for 4.5m was a dash distance (how far you could reasonably nip in a smoky lobby).

[nemodadog]

Committee wisdom - the original theory for 4.5m was a dash distance (how far you could reasonably nip in a smoky lobby).

Thanks for that Brian.

Hmm...a hop, skip and jump..lol. Given that on residential blocks of flats the residents 'in theory' dont escape on mass ie they stay in their apartments awaiting rescue...the travel distance is presumably for the fire fighters then?... if so, given modern day advancement in safety equipment, makes to my mind the travel distance a matter for discussion and not prescription??

If the travel distance is for the protection of the occupants...over the years, again with advancement of standards and equipment etc, the amount fo smoke released into the corridors should again be reduced, thereby allowing further flexibility in the travel distance?

[Mike Buckley]

It looks like a handover from the good old imperial days 4.5m = 5 yards and 7.5m is near enough 8 yards or roughly 5 paces and 8 paces.

I would suggest the idea was more along a psychological assessment of how far someone would be prepared to go in a smoke filled environment. i.e. in a smokefilled room a person would be prepared to advance about 5 paces and if they hadn't found the exit then they would turn back.

Like a lot of things it was probably based on some practical tests and has carried on on the basis of it seems to work so why change it.

[nemodadog]

Like a lot of things it was probably based on some practical tests and has carried on on the basis of it seems to work so why change it.

i guess so, but the driver for change is ever increasing pressure by Developers to fit more into less and that the change if supported by a holistic view of how the building works could lead to some flexibility here. Lets see ;-)

[wee brian]

Whilst we would normally leave residents in their flats, there are times when you want to evacuate them (e.g. when its all gone pete tong).

Thats when the "dash distance" comes in.

[nemodadog]

Whilst we would normally leave residents in their flats, there are times when you want to evacuate them (e.g. when its all gone pete tong).

Thats when the "dash distance" comes in.

lol..a hop skip and slightly further jump then to the 'apples and pears'!

[wee brian]

absolutely me old china